As much as I detest the song "Let It Go" from the movie Frozen, there are many times when we should heed the advice in the title of that song. Certain relationships fall into this category. 

Timothy knew all too well that there were people in his life not worthy of his time and energy. He was pouring into their lives but they were not being faithful with the teaching and blessing given. New wine was being poured into old wine skins and the wine skins were bursting and spilling all over the place.

"In Second Timothy 2:2, Paul wrote to his young disciple and told him, '...the things that thou has heard of me among many witnesses, the same commit thou to faithful men, who shall be able to teach others also.' The word 'commit' in this verse is a powerful key to building strong and lasting relationships. It is the Greek word parathou, which is a compound of the words, para and thou, the latter being a form of the word tithemi."

"When the words para and tithemi are compounded into one word, the new word is parathou, which means to come closely alongside someone else in order to put, place or deposit a part of oneself into that person."
(p.22, Sparkling Gems From The Greek 2, Renner)

So for Timothy, the time had come for him to sever ties with those old, fruitless and possible hurtful relationships and begin pouring into new, potential good ones. Timothy needed to start pouring the New Wine into new wine skins.

The context of the passage on old and new wine skins has to do with what Jesus was doing for His Disciples as He was with the disciples preparing them to be vessels of the Holy Spirit after He left (Matthew 9:14-17). The original question raised by John's disciples was - “How is it that we and the Pharisees fast often, but your disciples do not fast?” (Matt. 9:14) Christ's answer had two parts: (1) relationship and (2) proximity.

"Jesus answered, 'How can the guests of the bridegroom mourn while he is with them? The time will come when the bridegroom will be taken from them; then they will fast.'" (Matt. 9:15) 

Notice in the first part of Christ's answer relationship is established. Jesus identifies His Disciples as "guests" of not just any bridegroom, but "the bridegroom"'How can the guests of the bridegroom mourn while he is with them?'. In the same breath Jesus identifies Himself as The Bridegroom. Even though Jesus answers John's disciples, Christ really pours His teaching, His love and His life into His Disciples and those of faith seeking a miracle.  

In the latter part of this question and in the next statement, Christ mentions His proximity. First, Jesus mentions He is The Bridegroom who "is with them" now. Then He prophesies of a time when He "the bridegroom will be take from them"

Jesus was among many different people groups who heard and witnessed His teaching, compassion and power. However, Christ distanced Himself from certain people groups like the Pharisees and Sadducees whom He called a "brood of vipers" (Matt. 3:7)Christ was closer in proximity and heart to those that "listen to His voice" (John 10:27). These are the ones He poured into. These are the ones He drenched with the Holy Spirit.

Therefore, my challenge is for us to take example from Timothy and Christ by taking inventory of our wasteful resources we continually apply to fruitless and unfaithful relationships. After we stop this we need to begin pouring into other probable coworkers in the Kingdom who may even become good friends. Disappointment and hurt were probably part of the old relationships but new ones hold a hope of better things to come - From The Old To New Wineskins.